At the time of this study, serotonin reuptake inhibitors (SRIs) only benefited about 60% of patients who took them for OCD; even then, response was usually partial. 

This study by Drs. Schwartz and Black aimed to investigate whether there was a genetic abnormality in some people with OCD that caused the rapid metabolism of SRIs, and whether this was linked to the low effect these medications had on symptoms for them.